“Speed is a feature,” Google cofounder Larry Page once told me. “Speed can drive usage as much as having bells and whistles on your product. People really underappreciate it.”I thought of Page’s remark when I tried out a chatbot from the startup Groq last week. (The name comes from grok, golden era sci-fi writer Robert Heinlein’s term for deep understanding; it’s unrelated to Elon Musk’s chatbot Grok—more on which later.) Groq makes chips optimized to speed up the large language models that have...